1. Field of the Invention
The present invention is related, in general, to a portable apparatus, and more particularly, to a pointing device for portable apparatuses such as portable phones and personal digital assistants.
2. Description of the Related Art
Recent progress in functions of portable electronic apparatuses, such as portable phones and personal digital assistants, requires a user-friendly man-machine interface to help users make use of the functions.
A mouse is one of the prevailing man-machine interfaces. A mouse allows a user to move a pointer and to select an item shown on a display screen to provide the portable apparatus with the user's instructions.
A mouse, however, is not suitable for a portable apparatus. A large volume of a mouse makes it inconvenient to be used with a portable apparatus. In addition, a mouse requires considerable space to be operated by a user.
Other pointing devices are disclosed in Japanese Open Laid Patent Application (Jp-A-Heisei 4-123121, Jp-A-Heisei 5-224808, Jp-A-Heisei 11-167453). The disclosed pointing devices include an imaging device and operate the pointer in response to an image captured by the imaging device. However, none of the pointing device is designed for a portable apparatus.
A portable data assistant is disclosed in Japanese Open Laid Patent Application (Jp-A-Heisei 11-345073) which includes an image-based pointing device. The disclosed pointing device includes an imaging device capturing an image of the user of the portable apparatus. The pointing device detects the user's motion on the basis of the captured image, and operates in response to the user's motion. The user's motion includes a blink of the eye, a nod or a shake of the head, and a motion of the mouse.
An image editor apparatus including an image-based pointing device is disclosed in Japanese Open Laid Patent Application (Jp-A-Heisei 7-93089). The pointing device stores therein an image of a specific part of a user's body, such as the user's nose, and detects the movement of the specific part on the basis of an image captured by an imaging device. The pointing device then moves the pointer in response to the movement of the specific part. The document discloses that such a pointing device allows the image editor apparatus to be miniaturized or to be portable.